I've never handled nor seen much on the Ratical so I cannot comment specifically on performance, it but it seems like a nice bow..
The Edge on the otherhand, and I'll add the PSE Rally to the group as well.... I have handled and both are both great beginner bows. My wife has the PSE and my sister in law has the Edge and they're both nice bows and have huge adjustible weight range and DL. The Rally comes in a 50, 60 & 70 peak weight (my wife has the 70 and it 's adjustible down to 20 lbs) I believe the 50 lb model goes down to 5. The edge is a straight 5-70lbs and a tad shorter overall. So they can definitely grow with the bow. It's really a great feature, as for example my sister in law has her Edge set at 35lbs because at 40 after a few shots she struggles. And the weight as well as draw length can be adjusted on both of them without a press... Again they're both great for a beginner.
The Ratical is adjustible from 15-70 as well, but has an overall length of 29.25" which is pretty short, and also has the slowest FPS of the three, the Edge tags in at 31" with the highest FPS and finally the Rally at 33" and a FPS right the middle... That said the one thing I would suggest is to go to a bow shop and have her handle them all and see which feels the best in her hands, or even shoots the best if they'll let her shoot them all... Because no matter what works for someone else, or how great of reviews somethig gets what works for one may not for another so again, the best bet is getting a group of "like" bows and seeing which feels the best to her personally.
Depending on what she can draw the stinger 3G is a great choice and would be my pick out of the 4 provided she can draw it... But out of the three I'd choose the Rally.... But I also a PSE fan so my opinion may be jaded, lol. Again, go to a ProShop and get a bunch into her hands and see which feels "right" to her.. Good luck and let us know which route you go and how it works out!